This invention relates to photographic processing methods and compositions for black and white or monochrome silver halide emulsion films, and more particularly, to methods and compositions for convenient effective rapid processing of microfilm and x-ray film.
Many special purpose films that find use in the scientific, medical and information storage fields must produce fine grain, good quality images to be acceptable. Thus, in the scientific and medical fields detail of image must be readily ascertainable so that the viewer may correctly interpret the reproduction to pursue a further course of action or make an accurate diagnosis. In the information storage area, archival image quality, in addition to detail, is necessary for permanent record keeping and films which fade after a number of years are unacceptable. Additionally, x-ray must frequently be retained for medical and/or legal purposes for a period of time, often fixed by law.
Often, however, the foregoing desired properties of films finding utility in those areas, such as x-ray film and microfilm, are sacrificed to the necessary expedient of rapid photographic processing. The magnitude of microfilm generated by every day business, scientific and academic operations requires that commercial establishments be able to process such a film in as short a time as possible. For example, commercial institutions, such as banks and the like, microfilm records of daily transactions including account statements, checks, etc. and often desire return of the processed film prior to the start of the next business day.
Rapid processing of x-ray film is frequently of even greater importance than with other films. In addition, x-ray film, particularly dental x-ray film, must often be processed under conditions and with equipment that lack the sophisticated quality control of a commercial processing laboratory. Thus, in ongoing surgical procedures, x-ray images of the area of interest are many times desired by the physician in a matter of minutes or even seconds although the need for accuracy and detail remains an important criteria. Dental x-rays are often developed and studied while the patient remains in the dentist's chair awaiting further work. Under such circumstances the processing is desirably accomplished in the dentist's office under a minimum number of constraints due to the need to closely control processing variables. At the same time, acceptable image quality, such as density and contrast, must be preserved.